Supplemental Balance Sheet, Income Statement and Cash Flow Information (Details 6) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental cash flow information
Cash paid for income taxes	$ 100,749	$ 85,044	$ 53,759
Cash paid for interest, net of capitalized interest	239,637	250,045	208,212
Acquisitions of businesses:
Fair value of assets acquired	140,740		80,585
Goodwill	51,318		8,000
Liabilities assumed	(8,232)		(10,471)
Gain on acquisition			(13,114)
Future consideration payments (fair value)	(64,174)
Cash paid for acquisitions of businesses	119,652		65,000
Cash acquired in acquisitions of businesses	(2,681)		(9,541)
Cash paid for acquisition of business, net	$ 116,971		$ 55,459